1. Mosby items and derived items © 2007, 2005, 2002 by Mosby, Inc., an affiliate of Elsevier Inc. CHAPTER 18 Adrenergic-Blocking Drugs

2. Mosby items and derived items © 2007, 2005, 2002 by Mosby, Inc., an affiliate of Elsevier Inc. Adrenergic Blockers  Bind to adrenergic receptors, but inhibit or block stimulation of the sympathetic nervous system (SNS)   (alpha)-blockers and  (beta)-blockers

3. Mosby items and derived items © 2007, 2005, 2002 by Mosby, Inc., an affiliate of Elsevier Inc. Adrenergic Blockers (cont’d)  Have the opposite effect of adrenergic drugs  Also known as:  Adrenergic antagonists  Sympatholytics   -blockers,  -blockers, or  -  – blockers

4. Mosby items and derived items © 2007, 2005, 2002 by Mosby, Inc., an affiliate of Elsevier Inc. Adrenergic Blockers (cont’d) Sympatholytics inhibit—or LYSE— sympathetic stimulation

5. Mosby items and derived items © 2007, 2005, 2002 by Mosby, Inc., an affiliate of Elsevier Inc. Adrenergic Blockers (cont’d) Classified by the type of adrenergic receptor they block   1 and  2 receptors   1 and  2 receptors

6. Mosby items and derived items © 2007, 2005, 2002 by Mosby, Inc., an affiliate of Elsevier Inc.

7. Drug Effects and Indications Ergot alkaloids (  -blockers)  Constrict dilated arterioles in the brain  Used to treat vascular headaches (migraines)  Stimulate uterine contractions (oxytocics) and induce local vasoconstriction  Used to control postpartum bleeding

8. Mosby items and derived items © 2007, 2005, 2002 by Mosby, Inc., an affiliate of Elsevier Inc. Drug Effects and Indications (cont’d)  -blockers  Cause both arterial and venous dilation, reducing peripheral vascular resistance and BP  Used to treat hypertension  Effect on receptors on prostate gland and bladder decreased resistance to urinary outflow, thus reducing urinary obstruction and relieving effects of BPH

9. Mosby items and derived items © 2007, 2005, 2002 by Mosby, Inc., an affiliate of Elsevier Inc. Drug Effects and Indications (cont’d)  -blockers (cont'd)  Used to control and prevent hypertension in patients with pheochromocytoma  Phentolamine  Quickly reverses the potent vasoconstrictive effects of extravasated vasopressors such as norepinephrine or epinephrine  Restores blood flow and prevents tissue necrosis

10. Mosby items and derived items © 2007, 2005, 2002 by Mosby, Inc., an affiliate of Elsevier Inc.  -Blockers: Adverse Effects Body SystemAdverse Effects CardiovascularPalpitations, orthostatic hypotension, tachycardia, edema, dysrhythmias, chest pain CNSDizziness, headache, drowsiness, anxiety, depression, vertigo, weakness, numbness, fatigue

11. Mosby items and derived items © 2007, 2005, 2002 by Mosby, Inc., an affiliate of Elsevier Inc.  -Blockers: Adverse Effects (cont’d) Body SystemAdverse Effects GastrointestinalNausea, vomiting, diarrhea, constipation, abdominal pain OtherIncontinence, nosebleed, tinnitus, dry mouth, pharyngitis, rhinitis

12. Mosby items and derived items © 2007, 2005, 2002 by Mosby, Inc., an affiliate of Elsevier Inc. Common  -Blockers  ergotamine tartrate (Ergostat)  phenoxybenzamine HCl (Dibenzyline)  phentolamine (Regitine)  prazosin (Minipress)  tolazoline (Priscoline)

13. Mosby items and derived items © 2007, 2005, 2002 by Mosby, Inc., an affiliate of Elsevier Inc.  -Blockers  Block stimulation of  receptors in the SNS  Compete with norepinephrine and epinephrine  Selective and nonselective  -blockers  Nonselective  -blockers block both  1 and  2 receptors

14. Mosby items and derived items © 2007, 2005, 2002 by Mosby, Inc., an affiliate of Elsevier Inc.  Receptors  1 receptors  Located primarily on the heart   -blockers selective for these receptors are called cardioselective  -blockers

15. Mosby items and derived items © 2007, 2005, 2002 by Mosby, Inc., an affiliate of Elsevier Inc.  Receptors (cont’d)  2 receptors  Located primarily on smooth muscles of bronchioles and blood vessels

16. Mosby items and derived items © 2007, 2005, 2002 by Mosby, Inc., an affiliate of Elsevier Inc. Mechanism of Action Cardioselective (  1 )  Reduces SNS stimulation of the heart  Decreases heart rate  Prolongs SA node recovery  Slows conduction rate through the AV node  Decreases myocardial contractility, thus reducing myocardial oxygen demand

17. Mosby items and derived items © 2007, 2005, 2002 by Mosby, Inc., an affiliate of Elsevier Inc. Mechanism of Action (cont’d) Nonselective (  1 and  2 )  Effects on heart:Same as cardioselective  Bronchioles:Constriction, resulting in narrowing of airways and shortness of breath  Blood vessels:Vasoconstriction  Other effects

18. Mosby items and derived items © 2007, 2005, 2002 by Mosby, Inc., an affiliate of Elsevier Inc. Indications  Antiangina:Decreases demand for myocardial oxygen  Cardioprotective:Inhibits stimulation from circulating catecholamines  Class II antidysrhythmics

19. Mosby items and derived items © 2007, 2005, 2002 by Mosby, Inc., an affiliate of Elsevier Inc. Indications (cont’d)  Antihypertensive  Some are used to treat heart failure  Treatment of migraine headaches  Glaucoma (topical use)

20. Mosby items and derived items © 2007, 2005, 2002 by Mosby, Inc., an affiliate of Elsevier Inc. Adverse Effects:  -Blockers Body SystemAdverse Effects BloodAgranulocytosis, thrombocytopenia CardiovascularAV block, bradycardia, heart failure, peripheral vascular insufficiency CNSDizziness, mental depression, lethargy, hallucinations

21. Mosby items and derived items © 2007, 2005, 2002 by Mosby, Inc., an affiliate of Elsevier Inc. Adverse Effects: Adrenergic-Blocking Drugs  -blockers Body SystemAdverse Effects GastrointestinalNausea, dry mouth, vomiting, diarrhea, cramps, ischemic colitis OtherImpotence, rash, alopecia, bronchospasm

22. Mosby items and derived items © 2007, 2005, 2002 by Mosby, Inc., an affiliate of Elsevier Inc.  -Blockers: Examples  acebutolol (Sectral)  carvedilol (Coreg)  labetalol (Trandate)  metoprolol (Lopressor)  atenolol (Tenormin)  esmolol (Brevibloc)  sotalol (Betapace)  propranolol (Inderal)

23. Mosby items and derived items © 2007, 2005, 2002 by Mosby, Inc., an affiliate of Elsevier Inc. Adrenergic-Blocking Drugs: Nursing Implications  Assess for allergies and history of COPD, hypotension, cardiac dysrhythmias, bradycardia, heart failure, or other cardiovascular problems  Any preexisting condition that might be exacerbated by the use of these drugs might be a contraindication to their use

24. Mosby items and derived items © 2007, 2005, 2002 by Mosby, Inc., an affiliate of Elsevier Inc. Adrenergic-Blocking Drugs: Nursing Implications (cont’d)  Remember that  -blockers may precipitate hypotension  Remember that some  -blockers may precipitate bradycardia, hypotension, heart block, heart failure, and bronchoconstriction

25. Mosby items and derived items © 2007, 2005, 2002 by Mosby, Inc., an affiliate of Elsevier Inc. Adrenergic-Blocking Drugs: Nursing Implications (cont’d)  Avoid OTC medications because of possible interactions  Possible drug interactions may occur with:  Antacids (aluminum hydroxide type)  Antimuscarinics/anticholinergics  Diuretics and cardiovascular drugs  Neuromuscular blocking drugs  Oral hypoglycemic drugs

26. Mosby items and derived items © 2007, 2005, 2002 by Mosby, Inc., an affiliate of Elsevier Inc. Adrenergic-Blocking Drugs: Nursing Implications (cont’d)  Encourage patients to take medications as prescribed  These medications should never be stopped abruptly  Report constipation or the development of any urinary hesitancy or bladder distention

27. Mosby items and derived items © 2007, 2005, 2002 by Mosby, Inc., an affiliate of Elsevier Inc. Adrenergic-Blocking Drugs: Nursing Implications (cont’d)  Teach patients to change positions slowly to prevent or minimize postural hypotension  Avoid caffeine (excessive irritability)  Avoid alcohol ingestion and hazardous activities until blood levels become stable  Patients should notify their physician if palpitations, dyspnea, nausea, or vomiting occurs

28. Mosby items and derived items © 2007, 2005, 2002 by Mosby, Inc., an affiliate of Elsevier Inc.  -Blocking Drugs: Nursing Implications  Rebound hypertension or chest pain may occur if this medication is discontinued abruptly  Patients should notify their physician if they become ill and unable to take medication  Inform patients that they may notice a decrease in their tolerance for exercise; dizziness and fainting may occur with increased activity. Notify the physician if these problems occur

29. Mosby items and derived items © 2007, 2005, 2002 by Mosby, Inc., an affiliate of Elsevier Inc.  -Blocking Drugs: Nursing Implications (cont’d) Patients should report the following to their physician:  Weight gain of more than 2 pounds in 1 day or 5 lb within 1 week  Edema of the feet or ankles  Shortness of breath  Excessive fatigue or weakness  Syncope or dizziness

30. Mosby items and derived items © 2007, 2005, 2002 by Mosby, Inc., an affiliate of Elsevier Inc. Adrenergic-Blocking Drugs: Nursing Implications Monitor for adverse effects Monitor for therapeutic effects  Decreased chest pain in patients with angina  Return to normal BP and P  Other specific effects, depending on the use